从大麦到啤酒的β-葡聚糖及分析方法

β-葡聚糖是构成大麦胚乳细胞壁的重要成分，它大约占胚乳细胞壁组成的70％。大麦中β-葡聚糖的含量一般在2％～8％之间，大麦品种不同是导致β-葡聚糖含量不同的主要因素，另外种植地域和种植年度也会对大麦β-葡聚糖含量产生影响。我国的大麦品种相对其它国家的大麦品种β-葡聚糖含量偏高，有关研究通过对我国100多个大麦品种的β-葡聚糖含量进行统计，发现我国大麦β-葡聚糖的平均含量为4．58％，而欧洲一些国家的大麦品种，以及澳大利亚和加拿大的大麦品种β-葡聚糖平均含量在3．7％～4．5％之间。我国大麦品种的β-葡聚糖又以新疆，西藏为高，其中新疆大麦β-葡聚糖的平均含量为5．09％（27个大麦基因型的平均值），西藏大麦β-葡聚糖的平均含量为5．25％（75个大麦基因型的平均值）。     

山西冬性大麦品种培曲性能研究

为了研究山西产地来源的冬性大麦品种作为清香型白酒制曲原料的可行性，本研究以山西冬性大麦品种为研究对象，通过对比分析山西冬性大麦品种与清香型白酒制曲大麦品种的理化指标、培曲过程中理化指标的变化规律以及出房大曲、投产大曲的质量，研究其制曲性能。结果表明：该山西冬性大麦品种淀粉含量为58.12%，蛋白质含量为15%,3 d发芽率为96%,5 d发芽率为99%，水敏感性为3.00%，属于淀粉含量较低、蛋白质含量较高、水敏感性较低的大麦品种；二者在培曲过程理化指标变化趋势无显著性差异，在培曲过程中，山西冬性大麦品种曲温稍高于清香型白酒现用品种大麦，酸度、糖化力与液化力稍低于清香型白酒现用品种大麦，可能与其理化特性有关；山西冬性大麦品种出房大曲上霉均匀，有典型的曲香味，优质曲率为83%，水分为21.2%±0.8%，酸度为0.9 mmol/10 g±0.1 mmol/10 g，糖化力为1356.97 mg葡萄糖/g·h±125.2 mg葡萄糖/g·h，液化力为2.67 g淀粉/g·h±1.01 g淀粉/g·h，达到清香型白酒出房大曲的质量要求；山西冬性大麦品种投产大曲水分为12.2%±0.6%，酸度...     

大麦品种鉴定及其应用

通过聚丙烯凝胶电泳法获得大麦品种的特征图谱，即其醇溶蛋白的“指纹”，从而可以鉴别大麦的品种及其纯度。     

地产大麦制麦、酿酒试验研究

内蒙地区大麦种植已有多年，基本作为饲料使用。最近几年引进外地品种，如丹麦的付八，美国的蒙克尔，都有较大的种植面积。这些大麦的酿造性能如何？应包头市科委要求，受包头种子公司委托，对内蒙地区种植的大麦进行了酿造试验，以选择出适用啤酒酿造的大麦品种。试验内容和总体安排如下。     

欧洲酿造大麦的品种分布与品质特性

本文详述了欧洲大麦品种情况，全球酿造大麦年产量约16200万吨，其中37％产于欧洲。欧洲是世界上最大的酿造大麦产区，也是最大的酿造大麦和麦芽出口商，具有举足轻重的地位。     

大理州大麦的特性及制麦工艺控制

本文基于大理州广泛种植大麦品种的颗粒、蛋白质、水分及萌发状况等指标，分析了近几年大麦特性的变化，且对大麦种植和品种改良提出了浅显的见解。     

大麦品种籽粒、制粉和黏度特性研究

以13个大麦品种为材料,系统的分析了大麦品种的籽粒、制粉和黏度特性品质及它们之间的相关性,并结合适宜后续食品加工的原料特性参数,初步选取了适宜加工的大麦品种,旨在为大麦的深加工发展提供理论依据。     

高梁和大麦芽中金属离子对蛋白酶活生的影响

钙离子能增强大麦芽的蛋白酶活性，镁离子在高粱芽中产生了相似的作用。在高粱和大麦芽里，金属离子，如锌离子和铁离子抑制了谷芽中的蛋白酶活性.研究‘Chariot’大麦和一些高梁品种，蛋白酶活性在第三天增加且在第四天降低，研究‘Puffin’大麦和其它一些高粱品种，蛋白酶活性在第四天增加且在第五天降低。结果认为：在谷芽制造期间，高粱和大麦品种的遗传特性影响了蛋白酶水解的模式，且有其它不了解的谷类品种特性。     

浅谈国产甘肃大麦的制麦特性

制麦工艺随着大麦品种、收获年限、栽培条件、种植区域等不同应进行不同的调整。我们针对国产甘肃大麦进行试验，以确定适合甘肃大麦的制麦工艺。下面对去年国产甘啤3号大麦的制麦工艺，谈谈个人的体会。[第一段]     

游离花青素原（ANT—13）对大麦制麦芽品质和农学特性的影响

含有游离了花青素原（ＡＮＴ）的大麦，可以用于酿造具有优良的雾浊稳定性的啤酒。但由于经济指标的原因，适于耕种制麦芽用含游离花青素原大麦美国西部，已不发展该品种，从ＮＡＴ－１３５１７和栽培的Ｈａｒｒｉｎｇｔｏｎ品种一次收获衍 的两个试验品种，初筛游离花青素原的时候，孤立的观测了前述的改进型的游离花青互原特性。对这些试验品种（子代种）进行复筛研究时，测定了游离花青素原特性对大麦农学性能和制品质的影响。     

Varietal identification of single seeds of barley by analysis of hordein polypeptides

Methods for the extraction and separation of hordein fractions from single or half-seeds of barley have been evaluated. Sodium dodecylsulphate-polyacrylamide gel electrophoresis at pH 8.9 gave rapid and reproducible separations of reduced and alkylated hordein, and this system was used to analyse hordein fractions from 88 barley varieties. On the basis of this character the varieties can be divided into 29 groups, each containing between one and 25 varieties. The largest group can be further divided into four subgroups on the basis of minor hordein polypeptide differences revealed by a second electrophoretic system, urea polyacrylamide gel electrophoresis at pH 4.6. Of the samples of the varieties studied, all except five contained seed homogeneous with respect to hordein polypeptide pattern. It is concluded that analysis of hordein polypeptide patterns from single seeds is of great potential value, both for the commercial identification of grain samples and as an aid to existing techniques for the establishment of varietal distinctness.     

THE USE OF HORDEIN FRACTIONS TO ESTIMATE PROTEOLYTIC ACTIVITY IN BARLEY AND MALT

When the natural barley protein, hordein, is used as a substrate for the assay of exopeptidase and endopeptidase activity in green malts, the enzymic activities found differ significantly from those obtained using non-barley substrates such as dipeptides, gelatin or haemoglobin. Malts having similar total levels of carboxypeptidases as measured using non-barley substrates showed considerable variation in the extent to which these enzymes break down barley hordein. Malts also varied more in their endopeptidase activity with hordein than in their ability to digest gelatin or haemoglobin. Analyses of hordein by gel chromatography and gel electrophoresis indicate that it consists of eight main components, which can be divided into three groups of proteins, with molecular weights in the regions of 15,000, 65,000 and ≥ 100,000. Barley samples differed in their relative contents of these proteins and this variation could be rapidly assessed using gel electrophoresis.     

A comparison of methods for the extraction and separation of hordein fractions from 29 barley varieties

Methods have been developed for extracting and comparing the hordein fractions of barley seed as a means of identifying different varieties. A rapid method involving a single extraction with 55% (v/v) propan-2-ol+2% (v/v) 2-mercaptoethanol at 60°C removed slightly less nitrogen from milled grain than a more detailed procedure in which three sequential extractions were made with the same solvent. The hordein fractions extracted by these two procedures were alkylated and their component poly-peptides separated by four one-dimensional and two two-dimensional systems. The results showed that the hordein extracted by both techniques had the same polypeptide composition and thus the rapid method was satisfactory for use in comparing varieties. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectric focusing were used to compare the polypeptide composition of the hordein fractions from 29 varieties. Using the former system a total of 11 different patterns were recognised while further small differences between several varieties were revealed by isoelectric focusing or two-dimensional analysis. If the polypeptide patterns obtained by these techniques are considered in conjunction with other grain characters it should be possible to identify almost all of the 29 varieties.     

HORDEIN IN BARLEY AND MALT—A REVIEW

The chemical nature of hordein and current methods of extraction and fractionation are reviewed. The importance of hordein in identifying barley varieties and in predicting and assessing malting performance is discussed. Proteolytic breakdown of hordein during malting and mashing is summarized and the composition of hordein from barley, malt and spent grains is compared.     

Day‐length effects on protein localisation affect water absorption in barley (Hordeum vulgare) grains

BACKGROUND: Hordeins are major storage proteins of barley (Hordeum vulgare L.) grains and are considered to influence malting and brewing by forming a matrix surrounding the starch granules which affects the release of fermentable sugars. However, the extent to which environmental factors affect hordein location, and the impact of this on malting performance, have not so far been studied. Therefore the relationship of hordein location to water uptake and malting quality were studied by growing barley cv. Barke under different daylengths (14 h and 18 h of light) in controlled environment conditions. RESULTS: Differences in the locations of hordein storage proteins were observed, with C hordein being located more deeply within the endosperm of both developing grains at 35 days after anthesis and in mature grains under long‐day conditions. This deeper location of C hordein was correlated positively with water uptake during the steeping phase of malting. CONCLUSION: An effect of environment (daylength) on the localisation of C hordein was demonstrated. This difference in hordein localisation was also associated with differences in malting quality with water uptake in the steeping phase being associated positively with the deeper location of C hordein. These results indicate that environmental effects on protein location may affect malting performance of barley grains. Copyright © 2012 Society of Chemical Industry     

Barley and Malt Proteins and Proteinases: III. A Simple Method for Estimating the Combined Actions of Malt Proteinases and the Extent of Protein Degradation during Malting

The activities of barley and malt proteinases have been measured using haemoglobin and the highly degradable barley protein fraction (HDBPF) in malting and feed barley varieties. In conjunction, the barley and malt total protein and its components: hordein, glutelin, soluble proteins and free amino nitrogen (FAN) as well as Kolbach index were investigated. The comparative analysis of results revealed that the general grain modification index of Kolbach (KI), which was higher in malting varieties, was much more strongly associated with the levels of hordein degraded during malting than any other parameter investigated. The KI levels were also correlated with the increase in the levels of FAN, but not with the increase in the levels of soluble protein or changes in the glutelin component. The changes in total proteinase activity were low and cannot account for the increase in KI or the degraded hordein. The levels of total proteinase activity in both feed and malting barley varieties were similar. The results suggest that estimation of the levels of degraded hordein, during malting, is a sensitive indicator of the total proteolytic action of proteinases as well as the degradability of the reserve proteins. Therefore, we recommend measuring the amounts of hordein degraded during malting for the assessment of the impacts of grain protein and proteinases on malting barley quality of different varieties, in addition to KI and FAN.     

INHIBITION BY HORDEIN OF STARCH DEGRADATION

Large and small starch granules prepared from Proctor barley contain high levels of firmly bound protein. Experiments with α-amylase under simulated mashing conditions suggest that this protein limits the rate of starch breakdown during mashing. Gel electrophoresis shows hordein to be a principal component. Treatment with cysteine or malt endopeptidase changes the nature of the associated protein.     

PURIFICATION AND PROPERTIES OF MALT CARBOXYPEPTIDASES ATTACKING HORDEIN

Carboxypeptidases capable of releasing amino acids from barley hordein have been extracted and purified from malted barley. Three enzymes can be distinguished, with similar molecular weights but slightly different ionic characteristics and specificities. The malt carboxypeptidases preferentially attack peptides containing an aromatic amino acid, although other peptides, including those containing proline, are also attacked. The purified carboxypeptidase fractions reduce the viscosity of β-glucan extracted from endosperm cell walls. It is suggested that these enzymes may be instrumental in the initial solubilization of endosperm cell walls, possibly by the hydrolysis of the peptide component of these walls. The pH optima and heat stability data indicate that carboxypeptidases are crucial for the release of amino acids both from hordein, and from peptides derived from hordein during both malting and mashing.     

Use of acid gel electrophoresis in the characterisation of ‘B’ hordein protein in relation to malting quality and mildew resistance of barley

The ‘B’ polypeptides of the storage protein (hordein) of barley were studied in 84 varieties. On the basis of acid gel electrophoresis the varieties were classified into 13 distinct groups. Contrary to the suggestion that varieties preferred for malting tend to show less intensity of staining of the faster moving bands of the ‘B’ fraction of hordein, no consistent association was found in this study. Thus the malting potential of some varieties may be less affected by protein composition than by other factors. The genetic linkage between the Hor-2 locus, specifying the ‘B’ group of polypeptides, and the Mlalocus, determining resistance to powdery mildew (Erysiphe graminis), was illustrated by the similar groupings of varieties carrying the same resistance alleles, but exceptions were observed. Examples of the inheritance of hordein patterns are illustrated and discussed.